Terminal subprocesses inherit OPENAI_BASE_URL and other provider env vars loaded from ~/.hermes/.env, silently misrouting external CLIs like codex. Build a blocklist dynamically from the provider registry so new providers are automatically covered. Callers that truly need a blocked var can opt in via the _HERMES_FORCE_ prefix. Closes #1002 Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>